/*
 * Copyright (C) 2012 Google Inc.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package interactivespaces.activity.component;

import interactivespaces.InteractiveSpacesException;

import java.util.Map;

import com.google.common.collect.Maps;

/**
 * A simple implementation of the {@link ActivityComponentFactory}.
 * 
 * @author Keith M. Hughes
 */
public class SimpleActivityComponentFactory implements ActivityComponentFactory {

	/**
	 * The mapping of component names to the class implementing the component.
	 */
	private Map<String, Class<? extends ActivityComponent>> componentClassMap = Maps
			.newHashMap();

	@Override
	public void register(String componentName,
			Class<? extends ActivityComponent> componentClass) {
		componentClassMap.put(componentName, componentClass);
	}

	@Override
	public <T extends ActivityComponent> T newComponent(String componentName) {
		Class<? extends ActivityComponent> componentClass = componentClassMap
				.get(componentName);

		if (componentClass != null) {
			try {
				@SuppressWarnings("unchecked")
				T component = (T) componentClass.newInstance();

				return component;
			} catch (Exception e) {
				throw new InteractiveSpacesException(String.format(
						"Cannot create activity component %s", componentName),
						e);
			}
		} else {
			throw new InteractiveSpacesException(String.format(
					"Unknown activity component %s", componentName));
		}
	}
}
